Note 5 - Derivative Instruments (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]      
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net $ 9,101 $ 12,757 $ 1,151
Restricted Cash and Cash Equivalents $ 225 $ 1,464